As of the moment, there isn't an integrated way to add employees with QuickBooks Self-Employed. This is because this version of QuickBooks is intended for individuals with self-employed businesses.
That said, here's an article you can read to learn more about the nature of your new account in QuickBooks: QuickBooks Self-Employed Overview.
Need help performing any tasks related to your business account and company settings, click here to access and browse all articles for QuickBooks products. This reference contains most resources with steps on how you can update your data and security management, to name a few.
Don't hesitate to post again here if you have other questions or concerns with QuickBooks tasks and navigations. I'm always around happy to help. Stay safe and have a good one!